Thermostatic control valve



y 5, 1949- Y P. A. BIRCHFIELD 2,475,540

THERMOSTATIC CONTROL VALVE Filed Aug. 14, 1944 2 Sheets-Sheet 1 Fiied Aug. 14, 1944 July 5, 1949.

P. A. BIRCHFIELD 2,475,540

THERMOSTATIC CONTROL VALVE 2 Sheets-Sheet 2 Patented July 5, 1949 UNITED STATES PATENT OFFICE Claims.

This invention relates to valves, and more particularly to valves for automatically controlling the mixing of hot and cold fluids and insuring the discharge thereof at a substantially uniform temperature.

One of the objects of the invention is the provision of a new and improved valve for automatically controlling the mixing and discharge of hot and cold fluids that is especially useful in hotels, private dwellings, and the like, for automatically controlling the temperature of water for lavatories, tub and shower baths, and the like.

Another object of the invention is the provision of a new and improved valve that will automatically stop the now of a mixed fluid when the temperature rises above or falls below predetermined limits after the valve has been set to deliver the mixed fluid at a predetermined temperature.

A further object of the invention is the provision of a new and improved mixing valve that may be readily adjusted to deliver a mixture of hot and cold water at a predetermined temperature, and automatically maintain that temperature within predetermined limits.

Another object of the invention is the provision of a new and improved mixing and control valve that is manually operated to control the flow of a mixed hot and cold liquid, together with means for normally automatically maintaining said mixture at a predetermined temperature, and for stopping the flow of said mixture when its temperature abnormally rises or falls above or below predetermined limits.

Another object of the invention is the provision of a new and improved mixing and control valve that may be manually operated for starting and stopping the flow of supply liquid, or for automatically controlling the temperature of the mixed fluids by normally maintaining the mixture at a substantially constant temperature.

A still further object of the invention is the provision of a new and improved automatically controlled mixing valve that is simple in construction, relatively inexpensive to manufacture, efficient in operation, and that may be easily and readily assembled.

Other and further objects and advantages of the invention will appear from the following description, taken in connection with the accompanying drawings in which Fig. 1 is a side elevation of the mixing valve;

Fig. 2 is an elevation similar to Fig. 1, taken at right angles thereto;

Fig. 3is a section on the line 3-3 of Fig. 1;

Fig. 4 is a section on the line l4 of Fig. 3;

Fig. 5 is a section on the line 55 of Fig. 2;

Fig. 6 is a vertical section similar to Fig. 2, but showing a modified form of the invention; and

Fig. 7 is a section on the line 'll of Fig. 6, with parts broken away.

In the use of mixtures of hot and cold water in lavatories, tub and shower baths, and in nu- .merous chemical processes and manufacturing industries, it is often desirable, or even necessary, that the mixture on its discharge be automatically maintained at a predetermined temperature, which may be varied as desired. It is also desirable, in certain uses, that means be provided for automatically cutting off the flow of the mixture when the temperature thereof, for any reason Whatever, rises above a predetermined maximum or falls below a predetermined minimum. The present invention seeks to accomplish these functions by utilizing a greatly simplified valve and control mechanism.

For the purpose of disclosure the drawings illustrate an embodiment of the invention especially useful in mixing and controlling the flow of hot and cold water for lavatories, baths, and the like. While the description will be confined principally to a device for this purpose, it is understood that the language used is for the purpose of disclosure only, and is not intended as words of limitation.

Referring now to the drawings, the reference character l0 designates the mixing valve, which comprises a casing ll having a cylindrical casing member or intermediate section or body portion l2, threaded at its upper end, to which is detachably connected a cap l3 having an ,axial downwardly extending projection iii rigidly connected to the inside-of the cap I3 and extending downwardly therefrom. The cap and downwardly extending projection are provided with an axial screw-threaded opening for receiving a threaded valve stem It, the lower end of which is enlarged for constituting a swivel head H, as will presently appear. The upper end of the cylindrical casing member I2 is beveled outwardly and upwardly, as at It, and the cap is provided with a downwardly and outwardly beveled surface, as at IS. The bevels l8 and I 9 cooperate to form a recess within which is mounted a com- 7 pressible gasket 2| for cooperating with a spool The casing member l2 has two inlet ports therein. This member is provided adjacent its upper end with a slot 22 (see Fig. 3), which constitutes one of the inlet ports for the mixing valve. It is also provided adjacent its lower end with an elongated slot 23 (Figs. 2 and 4), which constitutes the other inlet port for the mixing valve. The slot 22 constitutes an inlet port for the admission 'of the hot fluid, and the slot 23 constitutes an inl'et port for the admission of the cold fluid.

Surrounding or extending over the port 22 is an inlet plate 24, having its edges rigidly connected to the cylindrical member [2 (Figs. 1, 2 and 3). The plate is provided with-a threaded nipple or intake conduit 25, extending outwardly, as shown more clearly in Fig. 3 "of the drawing. This plate is offset outwardly at its upper intermediate portion so as to form with the cylindrical member l;2 an intake chamber 26 in communication with the inlet '22 (Fig.3) The nipple or coi1'd-uit25 is adapted tohave attached to it a co'nduitZ'I (Fig-3) for conducting hot water from a source of supply 'to the mixing valve, as will presently-appear. 7

Attached over theinletport 23 is a plate 23, which is offset outwardly-at its lower intermediate portion and. has its-edges integral with or welded-to the casing member [2 to form an inlet chamber'ze (Figs. 2 and 3) over the port 23. This plate is provided with an outwardly extending threaded projection 3|, to which a conduit 32 (Fig. 3) is attached, and'thisconduit. is adapted to conduct col'd water from a source of supply to the mixing valve. The cylindrical casing member I? is provided in its lower portion with elongated discharge slots or ports 33 and at opposite sides of the casing member l2, as shown more clearly in Fig. l of the drawing. The discharge ports 33 and '33 are slightly above the inlet port 23-for the cold liquid intake, as shown in Figsf2 and 4. A suitable bottom cap member '34 is secured over the lower end i the casing member [2, and is provided with g an axial downwardly extending threaded projection, discharge conduit, or nipple 35, which constitutes the discharge port 'for the-mixing valve [0. The bottomportion of the cap immediately above" the threaded portion is offset downwardly,

as at '36, to form a valve seat for .the discharge valve, as willpresently. appear.

The cap member is attached in any suitable manner, as by welding, to the cylindrical casing member [2. This cap member has its side walls at opposite sides thereof offset-outwardly to form withth'e lower end of the casing member [2 port bottom wall of the cap. member what will be termed ports '31, 31 in-communication with the 'port chamb'e'rs'3li, warespe'ctively, whereby water" or other liquid may pass from the mixing chamberdfl'through the ports 33, 33 and 31, 31, to

' the discharge. port 35.

Suitable means are provided within the casing I l for'shutting oif and for controlling the-passage ment of the invention, "a spool shaped member,

metal which for convenience of description will be termed the balanced spool valve or spool valve member 38, is provided for this purpose. This valve member may be made in any suitable manher, and. has cylindrical end portions with its central connecting portion greatly reduced in diameter, as at 53, to form the annular mixing chamber All between the spool valve and easing member l2. This chamber extends entirely around the spool valve, as shown in Figs. 3, 5, and 6.

In the form of construction shown, the central section of the spool valve 38 has its ends enlarged in diameter, as shown at 39 and 4| (Figs. 2 and 4), and telescoped over, and rigidly secured to, these enlarged ends are cap members 42 and 43. These cap members are cylindrical and form what may be considered pistons engaging the inner surface of the casing member [2 and form therewith a more or less leak-proof sliding joint. The lower cap member 43 has its central portion offset downwardly, as at M, and provided with an axial opening through which a threaded bolt d5 extends for attaching a disc valve 46 of fibre, or the like, to the underside ofthedownwardly offsetportion 44, bymeans of a clamping nut 60. The disc 66 constitutes a valve for the discharge passage 35, and is adapted to engage the seat '36 feature oflthe invention, since by using this mechanism for shutting off the passage of the liquid through the mixing valve, as well as utilizing the same forcontrolling the flow of themixture and for regulating the temperature thereof, the use of the conventional shut-off valves for'the hot and cold water conduits are eliminated-and the entire flow control and temperature regulating mechanism is thereby greatly simplified.

Theupper cap member 4'2i'sprovided with an enlarged axialopening 41 extending around the downwardly extending projection. l5, and has attached thereto in any suitable manner, as by soldering, brazing, or the. like, the upper-end of a bellows 48 which extends downwardly through said opening dljitslower end being attached to a block 49 .to which the swivel head I! is connected. The bloclcflQ is provided with a recess for receiving theiheadll, and a plate 5|, secured to the block, is. provided with an opening through which the valve stem l6 extends,.thereby swivell-ing connecting the valve stem [6 to the block M1. The block '49 isprovided with a downwardly extending .projection (52, "to which the upper end of'a coil sprin'gj53 is connected. The lower end of the spring 53"i's attached to a projec- 'tion 54 onithe bolt 45.

In order that the spool valve 38 shall operate automatically to control the mixing of the cold and hot water, and for dischargingthe mixture at a predetermined temperature, the spool valve is filled with a highly volatile or thermo-sensitive fluid, such as methyl alcohol, or the. like. The spool-valve is vm'adeof relatively thin sheet metal in order that the heat will readily be. conducted through the wall to the volatile material within thespool, thereby-providing 'forthe prompt automatic control of the temperatureof the mixed liquids. When the interior of the spool becomes heated the methyl alcohol, or othervolatile liquid, will expand, and this pressure-will tend to increasethevolume within thespool. But this volume can only incr ease ifflthespool valvemoves downwardlyagainstthe. tension of. the .spring 53. 'Wlin'the cold'water p'ort'isopened'too far, the

preponderance of cold water causes the gas within the spool to contract and the spring 53 elevates the spool valve.

It will thus be seen that the temperature of the discharged liquid is controlled by a thermosensitive device, or, from another point of view, it may be termed a pressure sensitive device, since the pressure developed within the spool valve member determines the relative position of this member, which position in turn controls the proportionate amounts of hot and cold water admitted to the mixing chamber.

The expansion and contraction of the fluid within the spool valve is utilized for controlling the relative amounts of hot and cold liquid that are admitted to the mixing chamber 49, as will now be described. For instance, assuming that the mixing valve is in the position shown in Fig. 2, if the temperature and volume of water entering the intake passage 22 is such as to raise the temperature of the mixed liquid, it will cause an expansion of the fluid within the spool valve, and this expansion in turn will cause the valve to move downwardly, thus closing, or partially closing, the hot water inlet port 22. On the other hand, if the mixed liquid in the mixing chamber becomes too cool, the fluid within the spool valve will contract and the tension of the spring 53 will elevate the spool valve for closing off the cold liquid flowing through the inlet port 23 (Fig. 2) and opening the port 22, so that the relative amounts of cold and hot Water, or other liquid, will be varied by admitting more hot water and less cold water.

The temperature of the mixture discharged from the mixing valve may be controlled within predetermined limits. These limits are set by raising and lowering the block 49 by rotating the valve stem [6, as by means of the valve wheel 55. When the mixing valve is closed, i. e., when the disc valve 46 is on its seat 36, no water passes into the discharge conduit 35, the cold water port 23 is open, and the hot water port 22 is closed, as will be obvious from an inspection of Fig. 2. When it is desired to open the valve and to set the mechanism so that water at a predetermined temperature will be discharged from the mixing valve, the valve stem 16 is rotated counterclockwise for elevating the spool 38, and with it the disc valve 46, which will permit the discharge of the mixed liquid from the mixing chamber.

It will be obvious from an inspection of Fig. 2 that when the valve 46 is closed the hot water port 22 will also be closed by the cap or piston 4-2, and the cold water port 23- will be open.

In opening the valve 46 the stem [6 is turned counterclockwise, elevating the balanced spool valve and gradually closing the cold water port 23 and gradually opening the hot water port 22. This movement is continued until the liquid discharged from the mixing valve is at the desired temperature, after which the device operates automatically to hold the temperature of the discharged liquid at substantially the predetermined amount. By turning the stem clockwise more cold and less hot liquid is admitted to the mixing chamber, and further turning of the stem in this same direction will finally seat the valve 46 and. close the discharge passage.

In the operation of the mixing valve, assuming the parts are in the position shown in Fig. 2, the hot water enters through the conduit or passage 25 through the intake chamber 26, port 22, and into the mixing chamber 40. The cold water simultaneously enters-through the passage 3|, in-

take chamber 29, port 23 and into the mixing chamber til, and mixes with the hot water. The mixture passes out into the port chambers 30, 30 (Fig. 4) through the outlet ports 33, 33 and from these chambers the mixture flows back into the casing l2 through passages 31, 31 beneath the spool valve 38, and is discharged through the discharge passage 35. In other words, the passage 33, 3t and 31, on one side of the casing, and the passage 33 30 and 31*, on the other, constitute what may be termed by-passes for the mixture in the mixing chamber to flow around the lower end of the spool valve to the discharge port.

Suitable means are provided for stopping the flow of the mixture if its temperature rises ma terially above or materially below a predetermined amount. For instance, if after the mixing valve has been set and the temperature of the hot liquid rises above the set orpredetermined amount, this will cause the spool to be lowered, gradually shutting off the port 22 and further opening the port 23. If the temperature still continues to rise, the volatile fluid withinthe spool will continue to expand, causing the spool to be lowered until the valve 36 finally closes and prevents the operation of the mixing valve. On the other hand, if the temperature of the mixture falls below the set or predetermined amount, the spool will rise, opening the port 22 for admitting more hot liquid and gradually closing the port 23 for shuttin off the cold liquid. If the temperature of the mixture for any reason whatever continues to fall and gets materially below that desired, the volatile fluid within the spool contracts and the spool continues to rise until the discharge ports 33. 33*, (Fig. are finally closed, thus preventing the further operation of the valve.

It will thus be seen that in the operation of the spool valve it may be manually operated to open and close the discharge valve 46, and may be set to operate at any predetermined temperature within its limit of operation. It will function to automatically mix hot and cold water, or other fluids, and maintain the discharging liquid at a predetermined temperature. It will automatically shut off the flow of liquid if for any reason whatever, during the nominal operation of the valve, the following conditions obtain:

1. The cold water fails; 2. The hot water fails; 3. The hot water turns cold; The cold water turns hot.

Any water or other liquid leaking past the lower endof the spool valve will find its way to the discharge port and will not affect the operation of the device. 1

While the casing l I is shown as being made of several parts Welded together, it is understood that it may be cast or otherwise constructed, as may be necessary or desirable.

In Fig. 6 is shown a modified form of the invention, which, for all practical purposes, is the preferred form of construction. The broad principle is the same as that already described, but the form shown in Fig. 6 contains refinements not present in the structures shown in the remaining figures.

In this form of construction the reference character 50 designates the mixing valve, which comprises a casing 5| which may be of cast portions, or it may be stamped in sections from sheet metal, having a lower portion 52 externally threaded at its upper end and a cap portion 53 threaded g'provided'with ca discharge .outlet 54, adapted :to have a discharge conduit. .attached thereto ;;in the: usual manner.. Theiopeningxfor thei'cdischarge -:is restricted .at what. willt'be :terme'd its upper 'end, vto tiorm a valve .openingr55 enlarged inlet chambers 59 and '6 l, respectively, :as .:will

These inlet .members are 1111-...

presently appear. ternally=threadedfor attachment torsuitablerconduitssleadingfrom .sources. of hot :andicoldrwater, :respectively, :where the valve is used in bath rooms. .The. inlet 51 is for the .hot liquid,=and

113116.11111813158 admits the cold'liquid which "are.

mixed in a mixing'chamber, as will bexdescribed .below.

Thehcap =member '53 is stepped and .the :first step 59 has its horizontal portion extending .over the lowersection; as shownin Fig-.6, for-engaging-a packing thrust cylindricaluring oragland member-4t for holding a packing ringmemberffi I .clamped :in position .to form a wateretig'ht joint, :asuwillipresently appear. The uppermost stepped por.tion.iis :provided'with an :axial openingxBZ, .through which the'cylin'drical portionxof 'aispring .seatfi3and valve stem 16B extend.

-A cylindrical zliner :64'is seated withinithe lower portion .of .thecasi-ng ZSI by .a present, and,..is :a-lso heldinits lowermost positionsagainst .the bottom .of the said lower portion. by .the' packing material 6 l which in turn is forced down: by. the ring-:10. Thisxring is clamped in aposition by the-cap-portion53,.asshown in Fig.1 6. 1

Theiliner member 64 is employed forinexpensively .forming chambers and valve openings, as will .=now. be described. This liner 215 :provided with a. slot or valve opening. 65 :adjacentaitsrupper iend;.incommunication with:what for convenience of description will .beutermed 1 the: hot wateriinl'et .chamber '59,. and at its opposite side :adjacent; its :lower end it is providedwith a slot or valve' opening 66 opposite the cold water; inlet chamber Bl. The liner 64 is also provided withaslot Gil-(Fig.

7), which is slightly above the slottii .andlwhich.

constitutes a discharge openingfor. the mixed hot and cold liquid. 'The' lower endof the liner is cut away to form a slot 68 between the liner andithe bottom wall wofthe lower section 52 of :the :".casing for cooperating with the slot 61 'in forming: a discharge opening for the imixedliquid.

The lower section 52 of the casing is provided withanofiset 69 .(Fig. 7) whichplace's the'slots '61:=and:68 in. permanent communication with one another, whereby the mixed liquid may "pass from the mixing chamber to'the dischargevalve opening55,i as :will' presently appear.

l suitablermeanscare provided for automatically controlling the mixing and discharge :of the liquid,

which willnow be described. Inrthe 'form of the" deviceillustrated in iFigsuG and '7, which is 'by way of exampleonly, thermally controlled' mechanism is employed for this purpose. =As;shown,'a spool orspo'oles-hape'd valve .member. H "is employed. This member comprises.endorcap membe'rs 1.2 and 13, which are of a d-iameterzto;.--slidably. engage the inner -.-walls .of. the; liner: member .68, as. shownin Fig. 6, :and'makeaclosefitvthere- .with... me. central restricted member t lt-circular with ahighlyvolatile or thermo-isensitive fluid, -.-such..as;methyl alcohol, or the like. .valvea'll is preferably made of heat-conducting .materiaL-and is-thin, so that it is [very sensitive .larged'zandnlgidly connected. to :the upper and .loweruqcap'zmembers 12, 1-3. The-central ,portion of the spool valve member H is spaced inwardly :from theliner 64,.and forms therewith a mixing chamber 15 which extends entirely around the "restricted: portion 14 of the spool valve H.

The inwardly extending flanges 16 and ll of theendccaps v.12, 1'3, constitute valve closures for :the openingstd andlifi. These flanges. are spaced apartuza distance substantially the same as the distance. between the. .slots 65, 6.6, so that when the slot 65 is wide open, as shown in Fig. 6, the

slot 66;will be closed. By-meansof this arrangementtheproportionate amount of hot and cold Waterzto 'constitutea mixture of .the desired temperaturezis admitted into the mixing chamber 15.

:Suitablemeans are provided for automatically adjusting-the spool valve H, so that the temperatureof the-mixture of the water discharged from'the valve maybe a predetermined amount.

ofthe. cap 12 is provided with an axial opening .18,.-and secu-redaround this opening is the open .end of :a metalbellows or Sylphon 19, the lower :end. of which is rigidly secured to a plate 8!. .Mounted within :the bellows is an internally threadedplug 8,2,Whi0h is secured to the plate z8l-as by means of a setscrew 83. It will thus be seen-that vtheinterior of the spool valve ll, out- 'wardly of .the metal bellows I9, is water and .gas tight.

:Inzorder-that .the spool valve H shall operate .tautomatically to control the mixing of the cold and hot water for discharging the mixture at a predetermined temperature, this space is filled The spool to thetemperature of the mixed liquid.

Hot waterentering through the slot 65 will .wetassume thatthe parts are in the position of :Fig. 6 the lowering of the spool valve 'will tend to .close'thehot water slot 65 and open the slot .fiflfor admitting cold water to the mixing chamber15..

The lower end' ofthe spool valve-member H .hasattached thereto a valve seat holder 84, and .thisholder is provided with a. recess on its lower.surfacev in whicha valve member 86 is seated. .The .valve member 86 maybe of any suitable material, such as fiber, rubber, or the like, andis adapted to seat on the bottom of the valve seat :56 .for closing the opening 55, as is .usual in .such valve constructions. .are held in assembled relation by a stud 81, which extends down .through the bottom wall of the cap The parts member 13 and is provided with an internally threaded axial opening which is engaged by the screw BiLsaidscrew extending through the valve ImembenBfi .andengaging in the:threaded open- ;ingin the. stud 81 for holding the parts in as- ..sembled relation.

.TheLblockor plug 82 is internally threaded for engaging the threaded valve stem 60, .and the ipper. .end of the valve stem is reduced'and .squared .andextends through a corresponding squaredopeningin. a. metalplate 88 embedded in ca han'dle'memberor knob of plastic or ,othersuitableimaterial', 89,: whereby, uponrotationofthe .handlezmemben 8 9,-.-the:stem'- 60 may lac-threaded into or unthreaded from the block 82 for raising and lowering the spool valve H, and with it the valve member 85. It will thus be seen that by turning th handle 89, and with it the valve stem 99, counterclockwise, the block 82 will be forced downwardly, and with it the spool l I, for closing the valve 89, and vice versa.

Assuming now that the handle or knob 89 has been turned counterclockwise for closing the valve 85, it is evident that if, while the valve is closed, the room temperature should materially increase, the volatile fluid within the spool will continue to expand and might, by this excessive pressure, rupture the bellows or injure the valve, or some of the parts thereof. Suitable means are provided for preventing excessive pressure developing within the valve member ll. In the form of construction shown, a spring 9| is provided for relieving the pressure. The spring 9| surrounds the valve stem 69 and abut-s against the spring u seat 63, which is non-rotatably mounted in the opening 62 in the cap member The lower end of the spring engages a spring seat 92, which rests on an anti-friction washer 93 held in adjusted position by a nut 94 held in locked posi tion on the Valve stem by a set nut 95. By means of this arrangement the valve stem 69 is free to slide upwardly through. the spring seat 63, and may rotate in the spring seats 63 and 92, independently of the spring.

When the valve 86 is closed and the temperature of the room increases materially, the ex pansion of the fluid within the spool valve H will tend to force the spool downwardly, and the reaction against the valve seat 56 will force the valve stem upwardly, against the compression of the spring 9|, for preventing excessive pressure developing within the spool H.

In the operation of the device, the knob or handle member 89 is turned clockwise for opening the valve, and assuming now that the valve has been opened to the position shown in Fig. 6 hot water will enter the mixing chamber through the passage 95, and this in turn will heat the ther- 1no-sensitive fluid within the spool through the thin walls thereof. The expansion of this therino-sensitive fluid will cause the spool valve H to move downwardly for closing off the admission of the heated liquid, and at the same time the slot 96 will be partially opened for admitting cold water to the mixing chamber.

If it is desired that the water being discharged from the valve at 54 be hotter, the handle or knob 39 is turned clockwise, which elevates the block 82, and with it the spool valve 1!, for opening the port 65 and for closing the port 66. .In Fig. .6 the port 65 is wide open and the port 66 closed. If it is desired that the valve be set so that the mixture is not so hot, the knob 89 is turned counterclockwise for lowering the valve H for partially closing the port 95 and partially opening the port 99.

After the desired temperature of the mixture has been obtained, the spool valve member will operate automatically for holding the temperature at the required amount, If, after setting the valve, the mixture for any reason increases in temperature, the thermo-sensitive fluid within the spool valve H will expand, thus causing the valve H to move downward, which in turn gradually closes the hot water port at 65 and opens the 'cold water port at 66, until the temperature is back to that at which the valve was set. If, however, for any reason, there is still further heating of the thermo-sensitivefluid, as when the cool water entering through the port 66 fails or becomes hot, the thermo-sensitive fluid will. expand and will finally cause the valve member 86 to engage the valve seat 56, thus closing the opening 55. On the other hand, if the valve is set to deliver water at a selected temperature and for any reason the mixture becomes cold, as when the hot water fails, the lowering of the temperature of the thermo-sensitive fluid within the spool valve "II will contract, thus causing the air pressure to be greater on the outside of the spool valve ll than the pressure of the thermo-sensitive fluid within the spool valve; and hence these unequal pressures will cause the spool to rise so the bellows 19 will occupy more space in the spool, and this in turn cuts off the cold water inlet 66. This continues until the temperature of the water within the mixing chamber is at such a low point as to cause the spool H to rise still further and close the exitvalve 61 in the sleeve 64, preventing any further water from flowing through the mixing chamber. i i 1 It will thus be seen that so long as the hot and oold.water supply remains constant and at constant temperatures, the spool valve in both forms of the device may be set to deliver hot and cold water at any desired temperature, and that even though the temperature of either the hot or cold water vary within broad limits the valve will automatically change t deliver the mixture at a selected temperature.

In event the hot water turns cold, or the cold water turns hot,1or either fails altogether, the valve will function to shut off the discharge of the liquid from the valve. Furthermore, in event the environment temperature in the room increases while the valve is closed, the construction is such as to prevent injury to the bellows or any other part of the valve.

In other words, there are six variables that are kept under control by this valve, as follows:

. Variable hot and cold water pressures; Variable hot and cold water volume;

. Variable temperature of hot water;

Variable temperature of cold water;

. Variable atmospheric temperature;

. Variable delivery temperature.

It is thought from the foregoing, taken in connection with the accompanying drawing, that the construction and operation of my device will be apparent to those skilled in the art, and that changes in size, shape, proportion and details of construction may be made without departing from the spirit and scope of the appended claims.

I claim as my invention:

1. A mixing valve for hot and cold liquids comprising a casing, hot and cold water inlets for said casing, a valve member having enlarged cy lindrical ends forming valves for controlling said inlets and having a constricted central portion forming with said casing a mixing chamber within said casing for mixing the water from said inlets,.a discharge outlet for discharging the mixture from said chamber, a valve carried by said Valve member for closing said outlet, manually operated means for opening and closing said last named valve, and means enclosed within said valve member for automatically controlling the mixing of hot and cold water discharged from said mixing chamber for maintaining said mixture at a predetermined temperature,

2. In a liquid mixing and temperature control valve, a casing, intake ports through the side wall of said casing iorhot and cold liquids, a single discharge portfor; said liquids, ahoilowzvalve member slidably. mounted-within-said' casingaand having a central reducedziportionaforming with the walls of" saidcasing almixingachamber; said valve member constituting: aivaiveforopening and closing said inlet ports, ametalbellowstrconnected to the outer end ofsaid-valvemember and:extending down into said'valves member, 1 a, blockrconnected to the inner end offsaidizbell'ows; a valve stem threaded" inv said: casing: and? swivelly connectedto said block, a spring-for connecting the lower end of said valve member tic said block, a discharge valvefor-saiddischarge port carried by said valve member,- and? discharge passages for conducting. the mixed liquids around th'e= lower end .of said valve memhen'from'saidmixing chamher to said dischargeport; said 'valvemember hav ing a thermo-s 'ens-itive liquid thereiniand said intake portsbeing'at. diiferentheights wherebv said discharge valve may -be opened and 'cl'osed by rotating said stemfbr 'admitting hotz and cold liquids to said mixing chambers so that the-mixed liquid will be dischar-gedlata predetermined temperature and be automaticallymaintainedrat that temperature. I

3. A mixing. and? thermall control: valve comprising a: casing, a; valve" member,- movably mounted within saidicasing and having a' restricted portion forming with said casing-- a mixing chamber, an intake por-t for admitting hot liquid to said mixing chamber' adaptedto be opened and closed by said valvemember; an in take port for admittingacold liq id to said-mixing chamber and adapted-tobaopened and closed by said valve member, the partsbeingl-so constructed that When said-*valve member-moves in one direction the' cold water portW-illbe gradually closed and the -hot* waterport gradually opened, and. vice versa, saidvalvdmember being hollow and filled with a'thermo-sensitive' fluid, a disdharge passage for said mixing chamber, means for manually setting said; valvemember at a predeterminedilpositionlforadischarging the mixedliquidlfrom said mixing,chamber at: apredetermined temperature, .saidmeans comprising a valve stem a. metalsbellowslconnectingsaid valve member to saidcstem whereby awhen: the temperature of the mixed liquid within said chamber increases; the: expansion of saidithermoesensitive fluid for" moving-said: valve: member: in one direction for admitting'toasaidi chamber an increased proportionate amountioff the.=co1dliquid, and means includinggai spring for movingthe valve member in ,theopposite direction-for admitting anincreased: proportionate amount offsaid hot liquid for raising the temperature o f th e liquid discharged from saidichamber;

4. A mixing valve comprising a-casing, hot and cold water inlets in said casing, discharge port for said casing,- a hollowsvalvemember-within said casing for opening one inlet while closing the other and vice versa, said-valve having a- :restricted portion cooperatingwitli said c-asingfor forming a mixing chamberfor mixing hot and cold liquids entering 'through said inlets; and means including a-bellows withinsaid valve member, spaced inwardlyefrom the-sidewalls of said member to form a chamber for containing "a' heat sensitive fluid for automatically controlling the movements of said valve member, and 'for closing said port when the temperature of the 1 mixed liquids rises above a predetermined amount-.7

5. A hot and cold watenmixing-valve comprising a casing having elongated; slotted inlets for the admission of hot-'andcoldliquid's; respectively,

2; discharge -port; a hollowlval'vemember, means on said valve-member for controllingthe relative amounts of hot and cold liquidscadmitted to said casing through said. inlets, said member' having its central portionconstricted in diameter to form with saidcasing a mixingschamber forsaid liquids surrounding said member; andimeansincluding a bellows element extendingits' full 'length. down into said" valvemember' for forming with said member a. receptacleiorcontaining a thermosensitive fluid for operating said valve member for controlling the temperature of the mixed liquids discharged from said :port.

6; A hot' and'-cold watei mixingvalve comprise ing a-casing having a'discharge opening, said'casing-having slotted inlets, chambers over said slottedinlets, inlet cond'uit'sforconducting: hot and coldiliquids to said chambers, respectively, a thin Walled hollowvalve" member having: enlarged closedends'slidable over said inlets for controlling the admission of het'andcoldliquids through said slotted inlets', respectively, saidvalve member having a restricted intermediate portion'surrounding; thesame andforming with the inner walls of said casing a mixing chamber, means including a I bellows within saidvalve member for automatically controlling themovements of said valve member for' maintaining the liquid discharged from said casing at a substantially constant temperature, adjustable means connected to said bellows and extending to the exterior of said casing f or adjusting said valve member for delivering water-'passing'through said valvememher at a substantially constant predetermined temperature, a valve for said discharge opening operated bysaid' valve member and resilient means for preventingexcessive-pressure developing Within said valvemember;

7. A mixing valve comprisinga casinghaving cold and'hot-water inletsand a discharge port, a'hollow valve member within-saidcasing for controlling said inlets" and port, said valve member having a restricted portion cooperating with said casing for forming a mixing chamber for liquids entering; said casing through said inlets; means for manually setting'said member for discharging the mixedliquidat apredetermined temperature and means including a bellows within-said valve member and having-its 'sidewalls cooperating with the side walls of saidmem-berfor'forming"a chamber "for" containing a; thermo-sensitive. fluid for automatically controlling the movements of said valve member for maintaining the liquid discharged: through. said port atia predetermined temperature. 7

8. A valve. for mixing two liquids of different temperatures comprising a casing defining amixing chamber andhaving a plurality of inletports and a singleoutletiport' opening into; the chamber at, spaced points, and a-device: for; opening and closing said ports includinga hollow'valve memberhaving aflexible wall, a manually'adjusta'ble element carried by" the casing engaging. said wall, and temperature responsive liquid in said chamber for supportingand moving said wall with respect'to the valve member to displace the latter in cooperation witlrandwith respect to saidmanually adjustableielement; said valve member sliding back and forthacross the inlet"p0rtsand hav ing a'valve element closing saidroutletport atone limit'of movementiofthe valve member, the positive displacement effort of'both theadjustable element and thezwall as supported by, the temperatureresponsive'liquid beingrfidditivewith respect to'thedisplacementofsaid valve member in said chamber to vary and determine the range of temperature of mixed liquids passing through said outlet port when open and to close said outlet port automatically when the temperature of mixed liquids varies to a point outside said range and manually when said manually adjustable element is moved to a predetermined point.

9. A thermo-sensitive valve comprising a cylinder having intake valve ports therein, a spoolshaped casing of thin heat conducting material provided with side and end walls and having the exteriors of its end portions cylindrical, smooth, and unobstructed and of materially greater diameter than its intermediate portion for forming closures for said intake valve ports, said valve having one of its end walls provided with an axial opening, a metal bellows extending through said opening and connected at one end to the portion of the end wall surrounding the opening, and a closure for the opposite end of said bellows for forming a closed chamber within said casing for containing a thermo-sensitive fluid.

10. A thermo-sensitive valve including a cylinder having ports therein and a spool-shaped sheet metal casing in the cylinder provided with side and end Walls and having its end portions cylindrical and of greater diameter than its intermediate portion to cooperate with the ports to provide a valving action, said valve having one of its end walls provided with an axial opening a metal bellows extending through said opening and connected at one end to the portion of the end wall surrounding the opening, a closure for the opposite end of said bellows for forming a closed chamber within said casing for containing a thermo-sensitive fluid, and a valve secured to the other end wall of said casing.

P. A. BIRCHFIELD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Babbin May 5, 1942 

